Complex post-larval dispersal processes in Atlantic cod revealed by age-based genetics and relatedness analysis

Marine Ecology Progress Series

Ian R. Bradbury¹  Jeffrey Hutchings¹  Paul V. R. Snelgrove¹  David Hardie¹  Ian G. Paterson¹  Benjamin J. Laurel¹  Corey J. Morris¹  Paul Bentzen¹  Robert S. Gregory¹  John B. Horne¹ 

关键词: Gadidae;    Kinship;    Newfoundland;    Marine dispersal;    Fisheries;    Northwest Atlantic;   

DOI  :  10.3354/meps11819

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Population connectivity among adult marine organisms is often attributed to dispersal during the egg/larval stage. However, post-larval dispersal may also influence connectivity, particularly when juvenile nursery habitats are separated from adult spawning habitats. Here we used age-based population genetics and kinship analysis to explore changes in population connectivity across life-history stages in Atlantic cod Gadus morhua. We genotyped 364 adult cod from the northwest Atlantic and 671 age-0 juveniles from 18 sites around eastern Newfoundland, with 72 and 15 microsatellite loci, respectively. Adult cod genotypes exhibited more population structure than was detected in juveniles across similar spatial scales. Both age classes had similar allelic diversities, but juveniles exhibited less genetic linkage and fewer departures from Hardy-Weinberg expectations than adults at the same loci. We detected significant kinship relationships in adult cod only within sampling locations, but 1 putative pair of juvenile kin was separated by >500 km. Collections of adults also displayed higher group relatedness compared to juveniles. Genetic differences between age classes are likely due to a combination of non-random mortality and non-random sorting of admixed juveniles into different adult habitats. Many studies overlook post-larval dispersal as a factor of marine population connectivity, but pre-adult relocation may be demographically and adaptively significant, in cod and other species.

【 授权许可】

Unknown